title: CREATE_SUBSCRIPTION(7)

summary: define a new subscription

text:
# CREATE_SUBSCRIPTION(7)

## NAME
CREATE_SUBSCRIPTION - define a new subscription

## SYNOPSIS

```
CREATE SUBSCRIPTION subscription_name

    CONNECTION 'conninfo'

    PUBLICATION publication_name [, ...]

    [ WITH ( subscription_parameter [= value] [, ... ] ) ]
```

## DESCRIPTION
CREATE SUBSCRIPTION adds a new logical-replication subscription. The user that creates a subscription becomes the owner of the subscription. The subscription name must be distinct from the name of any existing subscription in the current database.

A subscription represents a replication connection to the publisher. Hence, in addition to adding definitions in the local catalogs, this command normally creates a replication slot on the publisher.

A logical replication worker will be started to replicate data for the new subscription at the commit of the transaction where this command is run, unless the subscription is initially disabled.

To be able to create a subscription, you must have the privileges of the pg_create_subscription role, as well as CREATE privileges on the current database.

Additional information about subscriptions and logical replication as a whole is available at Section 29.2 and Chapter 29.

## PARAMETERS
subscription_name

The name of the new subscription.

CONNECTION 'conninfo'

The libpq connection string defining how to connect to the publisher database. For details see Section 32.1.1.

PUBLICATION publication_name [, ...]

Names of the publications on the publisher to subscribe to.

WITH ( subscription_parameter [= value] [, ... ] )

This clause specifies optional parameters for a subscription. The following parameters control what happens during subscription creation:

connect (boolean)

Specifies whether the CREATE SUBSCRIPTION command should connect to the publisher at all. The default is true. Setting this to false will force the values of create_slot, enabled and copy_data to false. (You cannot combine setting connect to false with setting create_slot, enabled, or copy_data to true.) Since no connection is made when this option is false, no tables are subscribed. To initiate replication, you must manually create the replication slot, enable the failover if required, enable the subscription, and refresh the subscription. See Section 29.2.3 for examples.

create_slot (boolean)

Specifies whether the command should create the replication slot on the publisher. The default is true. If set to false, you are responsible for creating the publisher's slot in some other way. See Section 29.2.3 for examples.

enabled (boolean)

Specifies whether the subscription should be actively replicating or whether it should just be set up but not started yet. The default is true.

slot_name (string)

Name of the publisher's replication slot to use. The default is to use the name of the subscription for the slot name. Setting slot_name to NONE means there will be no replication slot associated with the subscription. Such subscriptions must also have both enabled and create_slot set to false. Use this when you will be creating the replication slot later manually. See Section 29.2.3 for examples.

When setting slot_name to a valid name and create_slot to false, the failover property value of the named slot may differ from the counterpart failover parameter specified in the subscription. Always ensure the slot property failover matches the counterpart parameter of the subscription and vice versa. Otherwise, the slot on the publisher may behave differently from what these subscription options say: for example, the slot on the publisher could either be synced to the standbys even when the subscription's failover option is disabled or could be disabled for sync even when the subscription's failover option is enabled.

The following parameters control the subscription's replication behavior after it has been created:

binary (boolean)

Specifies whether the subscription will request the publisher to send the data in binary format (as opposed to text). The default is false. Any initial table synchronization copy (see copy_data) also uses the same format. Binary format can be faster than the text format, but it is less portable across machine architectures and PostgreSQL versions. Binary format is very data type specific; for example, it will not allow copying from a smallint column to an integer column, even though that would work fine in text format. Even when this option is enabled, only data types having binary send and receive functions will be transferred in binary. Note that the initial synchronization requires all data types to have binary send and receive functions, otherwise the synchronization will fail (see CREATE TYPE (CREATE_TYPE(7)) for more about send/receive functions). When doing cross-version replication, it could be that the publisher has a binary send function for some data type, but the subscriber lacks a binary receive function for that type. In such a case, data transfer will fail, and the binary option cannot be used.

If the publisher is a PostgreSQL version before 16, then any initial table synchronization will use text format even if binary = true.

copy_data (boolean)

Specifies whether to copy pre-existing data in the publications that are being subscribed to when the replication starts. The default is true. If the publications contain WHERE clauses, it will affect what data is copied. Refer to the Notes for details.

See Notes for details of how copy_data = true can interact with the origin parameter.

streaming (enum)

Specifies whether to enable streaming of in-progress transactions for this subscription. The default value is off, meaning all transactions are fully decoded on the publisher and only then sent to the subscriber as a whole. If set to on, the incoming changes are written to temporary files and then applied only after the transaction is committed on the publisher and received by the subscriber.

If set to parallel, incoming changes are directly applied via one of the parallel apply workers, if available. If no parallel apply worker is free to handle streaming transactions then the changes are written to temporary files and applied after the transaction is committed. Note that if an error happens in a parallel apply worker, the finish LSN of the remote transaction might not be reported in the server log.

synchronous_commit (enum)

The value of this parameter overrides the synchronous_commit setting within this subscription's apply worker processes. The default value is off. It is safe to use off for logical replication: If the subscriber loses transactions because of missing synchronization, the data will be sent again from the publisher.

A different setting might be appropriate when doing synchronous logical replication. The logical replication workers report the positions of writes and flushes to the publisher, and when using synchronous replication, the publisher will wait for the actual flush. This means that setting synchronous_commit for the subscriber to off when the subscription is used for synchronous replication might increase the latency for COMMIT on the publisher. In this scenario, it can be advantageous to set synchronous_commit to local or higher.

two_phase (boolean)

Specifies whether two-phase commit is enabled for this subscription. The default is false. When two-phase commit is enabled, prepared transactions are sent to the subscriber at the time of PREPARE TRANSACTION, and are processed as two-phase transactions on the subscriber too. Otherwise, prepared transactions are sent to the subscriber only when committed, and are then processed immediately by the subscriber.

The implementation of two-phase commit requires that replication has successfully finished the initial table synchronization phase. So even when two_phase is enabled for a subscription, the internal two-phase state remains temporarily “pending” until the initialization phase completes. See column subtwophasestate of pg_subscription to know the actual two-phase state.

disable_on_error (boolean)

Specifies whether the subscription should be automatically disabled if any errors are detected by subscription workers during data replication from the publisher. The default is false.

password_required (boolean)

If set to true, connections to the publisher made as a result of this subscription must use password authentication and the password must be specified as a part of the connection string. This setting is ignored when the subscription is owned by a superuser. The default is true. Only superusers can set this value to false.

run_as_owner (boolean)

If true, all replication actions are performed as the subscription owner. If false, replication workers will perform actions on each table as the owner of that table. The latter configuration is generally much more secure; for details, see Section 29.10. The default is false.

origin (string)

Specifies whether the subscription will request the publisher to only send changes that don't have an origin or send changes regardless of origin. Setting origin to none means that the subscription will request the publisher to only send changes that don't have an origin. Setting origin to any means that the publisher sends changes regardless of their origin. The default is any. See Notes for details of how copy_data = true can interact with the origin parameter.

failover (boolean)

Specifies whether the replication slots associated with the subscription are enabled to be synced to the standbys so that logical replication can be resumed from the new primary after failover. The default is false.

When specifying a parameter of type boolean, the = value part can be omitted, which is equivalent to specifying TRUE.

## NOTES
See Section 29.10 for details on how to configure access control between the subscription and the publication instance.

When creating a replication slot (the default behavior), CREATE SUBSCRIPTION cannot be executed inside a transaction block.

Creating a subscription that connects to the same database cluster (for example, to replicate between databases in the same cluster or to replicate within the same database) will only succeed if the replication slot is not created as part of the same command. Otherwise, the CREATE SUBSCRIPTION call will hang. To make this work, create the replication slot separately (using the function pg_create_logical_replication_slot with the plugin name pgoutput) and create the subscription using the parameter create_slot = false. See Section 29.2.3 for examples. This is an implementation restriction that might be lifted in a future release.

If any table in the publication has a WHERE clause, rows for which the expression evaluates to false or null will not be published. If the subscription has several publications in which the same table has been published with different WHERE clauses, a row will be published if any of the expressions (referring to that publish operation) are satisfied. In the case of different WHERE clauses, if one of the publications has no WHERE clause (referring to that publish operation) or the publication is declared as FOR ALL TABLES or FOR TABLES IN SCHEMA, rows are always published regardless of the definition of the other expressions. If the subscriber is a PostgreSQL version before 15, then any row filtering is ignored during the initial data synchronization phase. For this case, the user might want to consider deleting any initially copied data that would be incompatible with subsequent filtering. Because initial data synchronization does not take into account the publication publish parameter when copying existing table data, some rows may be copied that would not be replicated using DML. See Section 29.2.2 for examples.

Subscriptions having several publications in which the same table has been published with different column lists are not supported.

We allow non-existent publications to be specified so that users can add those later. This means pg_subscription can have non-existent publications.

When using a subscription parameter combination of copy_data = true and origin = NONE, the initial sync table data is copied directly from the publisher, meaning that knowledge of the true origin of that data is not possible. If the publisher also has subscriptions then the copied table data might have originated from further upstream. This scenario is detected and a WARNING is logged to the user, but the warning is only an indication of a potential problem; it is the user's responsibility to make the necessary checks to ensure the copied data origins are really as wanted or not.

To find which tables might potentially include non-local origins (due to other subscriptions created on the publisher) try this SQL query:

```
# substitute <pub-names> below with your publication name(s) to be queried
SELECT DISTINCT PT.schemaname, PT.tablename
FROM pg_publication_tables PT

     JOIN pg_class C ON (C.relname = PT.tablename)

     JOIN pg_namespace N ON (N.nspname = PT.schemaname),

     pg_subscription_rel PS
WHERE C.relnamespace = N.oid AND

      (PS.srrelid = C.oid OR

      C.oid IN (SELECT relid FROM pg_partition_ancestors(PS.srrelid) UNION

                SELECT relid FROM pg_partition_tree(PS.srrelid))) AND

      PT.pubname IN (<pub-names>);
```

## EXAMPLES
Create a subscription to a remote server that replicates tables in the publications mypublication and insert_only and starts replicating immediately on commit:

```
CREATE SUBSCRIPTION mysub

         CONNECTION 'host=192.168.1.50 port=5432 user=foo dbname=foodb'

        PUBLICATION mypublication, insert_only;
```

Create a subscription to a remote server that replicates tables in the insert_only publication and does not start replicating until enabled at a later time.

```
CREATE SUBSCRIPTION mysub

         CONNECTION 'host=192.168.1.50 port=5432 user=foo dbname=foodb'

        PUBLICATION insert_only

               WITH (enabled = false);
```

## COMPATIBILITY
CREATE SUBSCRIPTION is a PostgreSQL extension.

## SEE ALSO
ALTER SUBSCRIPTION (ALTER_SUBSCRIPTION(7)), DROP SUBSCRIPTION (DROP_SUBSCRIPTION(7)), CREATE PUBLICATION (CREATE_PUBLICATION(7)), ALTER PUBLICATION (ALTER_PUBLICATION(7))


title: CREATE_TABLE(7)

summary: define a new table

text:
# CREATE_TABLE(7)

## NAME
CREATE_TABLE - define a new table

## SYNOPSIS

```
CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE [ IF NOT EXISTS ] table_name ( [

  { column_name data_type [ STORAGE { PLAIN | EXTERNAL | EXTENDED | MAIN | DEFAULT } ] [ COMPRESSION compression_method ] [ COLLATE collation ] [ column_constraint [ ... ] ]

    | table_constraint

    | LIKE source_table [ like_option ... ] }

    [, ... ]
] )
[ INHERITS ( parent_table [, ... ] ) ]
[ PARTITION BY { RANGE | LIST | HASH } ( { column_name | ( expression ) } [ COLLATE collation ] [ opclass ] [, ... ] ) ]
[ USING method ]
[ WITH ( storage_parameter [= value] [, ... ] ) | WITHOUT OIDS ]
[ ON COMMIT { PRESERVE ROWS | DELETE ROWS | DROP } ]
[ TABLESPACE tablespace_name ]
CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE [ IF NOT EXISTS ] table_name

    OF type_name [ (

  { column_name [ WITH OPTIONS ] [ column_constraint [ ... ] ]

    | table_constraint }

    [, ... ]
) ]
[ PARTITION BY { RANGE | LIST | HASH } ( { column_name | ( expression ) } [ COLLATE collation ] [ opclass ] [, ... ] ) ]
[ USING method ]
[ WITH ( storage_parameter [= value] [, ... ] ) | WITHOUT OIDS ]
[ ON COMMIT { PRESERVE ROWS | DELETE ROWS | DROP } ]
[ TABLESPACE tablespace_name ]
CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE [ IF NOT EXISTS ] table_name

    PARTITION OF parent_table [ (

  { column_name [ WITH OPTIONS ] [ column_constraint [ ... ] ]

    | table_constraint }

    [, ... ]
) ] { FOR VALUES partition_bound_spec | DEFAULT }
[ PARTITION BY { RANGE | LIST | HASH } ( { column_name | ( expression ) } [ COLLATE collation ] [ opclass ] [, ... ] ) ]
[ USING method ]
[ WITH ( storage_parameter [= value] [, ... ] ) | WITHOUT OIDS ]
[ ON COMMIT { PRESERVE ROWS | DELETE ROWS | DROP } ]
[ TABLESPACE tablespace_name ]
where column_constraint is:
[ CONSTRAINT constraint_name ]
{ NOT NULL |

  NULL |

  CHECK ( expression ) [ NO INHERIT ] |

  DEFAULT default_expr |

  GENERATED ALWAYS AS ( generation_expr ) STORED |

  GENERATED { ALWAYS | BY DEFAULT } AS IDENTITY [ ( sequence_options ) ] |

  UNIQUE [ NULLS [ NOT ] DISTINCT ] index_parameters |

  PRIMARY KEY index_parameters |

  REFERENCES reftable [ ( refcolumn ) ] [ MATCH FULL | MATCH PARTIAL | MATCH SIMPLE ]

    [ ON DELETE referential_action ] [ ON UPDATE referential_action ] }
[ DEFERRABLE | NOT DEFERRABLE ] [ INITIALLY DEFERRED | INITIALLY IMMEDIATE ]
and table_constraint is:
[ CONSTRAINT constraint_name ]
{ CHECK ( expression ) [ NO INHERIT ] |

  UNIQUE [ NULLS [ NOT ] DISTINCT ] ( column_name [, ... ] ) index_parameters |

  PRIMARY KEY ( column_name [, ... ] ) index_parameters |

  EXCLUDE [ USING index_method ] ( exclude_element WITH operator [, ... ] ) index_parameters [ WHERE ( predicate ) ] |

  FOREIGN KEY ( column_name [, ... ] ) REFERENCES reftable [ ( refcolumn [, ... ] ) ]

    [ MATCH FULL | MATCH PARTIAL | MATCH SIMPLE ] [ ON DELETE referential_action ] [ ON UPDATE referential_action ] }
[ DEFERRABLE | NOT DEFERRABLE ] [ INITIALLY DEFERRED | INITIALLY IMMEDIATE ]
and like_option is:
{ INCLUDING | EXCLUDING } { COMMENTS | COMPRESSION | CONSTRAINTS | DEFAULTS | GENERATED | IDENTITY | INDEXES | STATISTICS | STORAGE | ALL }
and partition_bound_spec is:
IN ( partition_bound_expr [, ...] ) |
FROM ( { partition_bound_expr | MINVALUE | MAXVALUE } [, ...] )

  TO ( { partition_bound_expr | MINVALUE | MAXVALUE } [, ...] ) |
WITH ( MODULUS numeric_literal, REMAINDER numeric_literal )
index_parameters in UNIQUE, PRIMARY KEY, and EXCLUDE constraints are:
[ INCLUDE ( column_name [, ... ] ) ]
[ WITH ( storage_parameter [= value] [, ... ] ) ]
[ USING INDEX TABLESPACE tablespace_name ]
exclude_element in an EXCLUDE constraint is:
{ column_name | ( expression ) } [ COLLATE collation ] [ opclass [ ( opclass_parameter = value [, ... ] ) ] ] [ ASC | DESC ] [ NULLS { FIRST | LAST } ]
referential_action in a FOREIGN KEY/REFERENCES constraint is:
{ NO ACTION | RESTRICT | CASCADE | SET NULL [ ( column_name [, ... ] ) ] | SET DEFAULT [ ( column_name [, ... ] ) ] }
```

## DESCRIPTION
CREATE TABLE will create a new, initially empty table in the current database. The table will be owned by the user issuing the command.

If a schema name is given (for example, CREATE TABLE myschema.mytable ...) then the table is created in the specified schema. Otherwise it is created in the current schema. Temporary tables exist in a special schema, so a schema name cannot be given when creating a temporary table. The name of the table must be distinct from the name of any other relation (table, sequence, index, view, materialized view, or foreign table) in the same schema.

CREATE TABLE also automatically creates a data type that represents the composite type corresponding to one row of the table. Therefore, tables cannot have the same name as any existing data type in the same schema.

The optional constraint clauses specify constraints (tests) that new or updated rows must satisfy for an insert or update operation to succeed. A constraint is an SQL object that helps define the set of valid values in the table in various ways.

There are two ways to define constraints: table constraints and column constraints. A column constraint is defined as part of a column definition. A table constraint definition is not tied to a particular column, and it can encompass more than one column. Every column constraint can also be written as a table constraint; a column constraint is only a notational convenience for use when the constraint only affects one column.

To be able to create a table, you must have USAGE privilege on all column types or the type in the OF clause, respectively.

## PARAMETERS
TEMPORARY or TEMP

If specified, the table is created as a temporary table. Temporary tables are automatically dropped at the end of a session, or optionally at the end of the current transaction (see ON COMMIT below). The default search_path includes the temporary schema first and so identically named existing permanent tables are not chosen for new plans while the temporary table exists, unless they are referenced with schema-qualified names. Any indexes created on a temporary table are automatically temporary as well. The autovacuum daemon cannot access and therefore cannot vacuum or analyze temporary tables. For this reason, appropriate vacuum and analyze operations should be performed via session SQL commands. For example, if a temporary table is going to be used in complex queries, it is wise to run ANALYZE on the temporary table after it is populated.

Optionally, GLOBAL or LOCAL can be written before TEMPORARY or TEMP. This presently makes no difference in PostgreSQL and is deprecated; see Compatibility below.

UNLOGGED

If specified, the table is created as an unlogged table. Data written to unlogged tables is not written to the write-ahead log (see Chapter 28), which makes them considerably faster than ordinary tables. However, they are not crash-safe: an unlogged table is automatically truncated after a crash or unclean shutdown. The contents of an unlogged table are also not replicated to standby servers. Any indexes created on an unlogged table are automatically unlogged as well. If this is specified, any sequences created together with the unlogged table (for identity or serial columns) are also created as unlogged.

IF NOT EXISTS

Do not throw an error if a relation with the same name already exists. A notice is issued in this case. Note that there is no guarantee that the existing relation is anything like the one that would have been created.

table_name

The name (optionally schema-qualified) of the table to be created.

OF type_name

Creates a typed table, which takes its structure from the specified composite type (name optionally schema-qualified). A typed table is tied to its type; for example the table will be dropped if the type is dropped (with DROP TYPE ... CASCADE). When a typed table is created, then the data types of the columns are determined by the underlying composite type and are not specified by the CREATE TABLE command. But the CREATE TABLE command can add defaults and constraints to the table and can specify storage parameters.

column_name

The name of a column to be created in the new table.

data_type

The data type of the column. This can include array specifiers. For more information on the data types supported by PostgreSQL, refer to Chapter 8.

COLLATE collation

The COLLATE clause assigns a collation to the column (which must be of a collatable data type). If not specified, the column data type's default collation is used.

STORAGE { PLAIN | EXTERNAL | EXTENDED | MAIN | DEFAULT }

This form sets the storage mode for the column. This controls whether this column is held inline or in a secondary TOAST table, and whether the data should be compressed or not. PLAIN must be used for fixed-length values such as integer and is inline, uncompressed. MAIN is for inline, compressible data. EXTERNAL is for external, uncompressed data, and EXTENDED is for external, compressed data. Writing DEFAULT sets the storage mode to the default mode for the column's data type. EXTENDED is the default for most data types that support non-PLAIN storage. Use of EXTERNAL will make substring operations on very large text and bytea values run faster, at the penalty of increased storage space. See Section 65.2 for more information.

COMPRESSION compression_method

The COMPRESSION clause sets the compression method for the column. Compression is supported only for variable-width data types, and is used only when the column's storage mode is main or extended. (See ALTER TABLE (ALTER_TABLE(7)) for information on column storage modes.) Setting this property for a partitioned table has no direct effect, because such tables have no storage of their own, but the configured value will be inherited by newly-created partitions. The supported compression methods are pglz and lz4. (lz4 is available only if --with-lz4 was used when building PostgreSQL.) In addition, compression_method can be default to explicitly specify the default behavior, which is to consult the default_toast_compression setting at the time of data insertion to determine the method to use.

INHERITS ( parent_table [, ... ] )

The optional INHERITS clause specifies a list of tables from which the new table automatically inherits all columns. Parent tables can be plain tables or foreign tables. Use of INHERITS creates a persistent relationship between the new child table and its parent table(s). Schema modifications to the parent(s) normally propagate to children as well, and by default the data of the child table is included in scans of the parent(s).

If the same column name exists in more than one parent table, an error is reported unless the data types of the columns match in each of the parent tables. If there is no conflict, then the duplicate columns are merged to form a single column in the new table. If the column name list of the new table contains a column name that is also inherited, the data type must likewise match the inherited column(s), and the column definitions are merged into one. If the new table explicitly specifies a default value for the column, this default overrides any defaults from inherited declarations of the column. Otherwise, any parents that specify default values for the column must all specify the same default, or an error will be reported.

CHECK constraints are merged in essentially the same way as columns: if multiple parent tables and/or the new table definition contain identically-named CHECK constraints, these constraints must all have the same check expression, or an error will be reported. Constraints having the same name and expression will be merged into one copy. A constraint marked NO INHERIT in a parent will not be considered. Notice that an unnamed CHECK constraint in the new table will never be merged, since a unique name will always be chosen for it.

Column STORAGE settings are also copied from parent tables.

If a column in the parent table is an identity column, that property is not inherited. A column in the child table can be declared identity column if desired.

PARTITION BY { RANGE | LIST | HASH } ( { column_name | ( expression ) } [ opclass ] [, ...] )

The optional PARTITION BY clause specifies a strategy of partitioning the table. The table thus created is called a partitioned table. The parenthesized list of columns or expressions forms the partition key for the table. When using range or hash partitioning, the partition key can include multiple columns or expressions (up to 32, but this limit can be altered when building PostgreSQL), but for list partitioning, the partition key must consist of a single column or expression. Range and list partitioning require a btree operator class, while hash partitioning requires a hash operator class. If no operator class is specified explicitly, the default operator class of the appropriate type will be used; if no default operator class exists, an error will be raised. When hash partitioning is used, the operator class used must implement support function 2 (see Section 36.16.3 for details).

A partitioned table is divided into sub-tables (called partitions), which are created using separate CREATE TABLE commands. The partitioned table is itself empty. A data row inserted into the table is routed to a partition based on the value of columns or expressions in the partition key. If no existing partition matches the values in the new row, an error will be reported.

See Section 5.12 for more discussion on table partitioning.

PARTITION OF parent_table { FOR VALUES partition_bound_spec | DEFAULT }

Creates the table as a partition of the specified parent table. The table can be created either as a partition for specific values using FOR VALUES or as a default partition using DEFAULT. Any indexes, constraints and user-defined row-level triggers that exist in the parent table are cloned on the new partition. The partition_bound_spec must correspond to the partitioning method and partition key of the parent table, and must not overlap with any existing partition of that parent. The form with IN is used for list partitioning, the form with FROM and TO is used for range partitioning, and the form with WITH is used for hash partitioning.

partition_bound_expr is any variable-free expression (subqueries, window functions, aggregate functions, and set-returning functions are not allowed). Its data type must match the data type of the corresponding partition key column. The expression is evaluated once at table creation time, so it can even contain volatile expressions such as CURRENT_TIMESTAMP.

When creating a list partition, NULL can be specified to signify that the partition allows the partition key column to be null. However, there cannot be more than one such list partition for a given parent table. NULL cannot be specified for range partitions.

When creating a range partition, the lower bound specified with FROM is an inclusive bound, whereas the upper bound specified with TO is an exclusive bound. That is, the values specified in the FROM list are valid values of the corresponding partition key columns for this partition, whereas those in the TO list are not. Note that this statement must be understood according to the rules of row-wise comparison (Section 9.25.5). For example, given PARTITION BY RANGE (x,y), a partition bound FROM (1, 2) TO (3, 4) allows x=1 with any y>=2, x=2 with any non-null y, and x=3 with any y<4.

The special values MINVALUE and MAXVALUE may be used when creating a range partition to indicate that there is no lower or upper bound on the column's value. For example, a partition defined using FROM (MINVALUE) TO (10) allows any values less than 10, and a partition defined using FROM (10) TO (MAXVALUE) allows any values greater than or equal to 10.

When creating a range partition involving more than one column, it can also make sense to use MAXVALUE as part of the lower bound, and MINVALUE as part of the upper bound. For example, a partition defined using FROM (0, MAXVALUE) TO (10, MAXVALUE) allows any rows where the first partition key column is greater than 0 and less than or equal to 10. Similarly, a partition defined using FROM ('a', MINVALUE) TO ('b', MINVALUE) allows any rows where the first partition key column starts with "a".

Note that if MINVALUE or MAXVALUE is used for one column of a partitioning bound, the same value must be used for all subsequent columns. For example, (10, MINVALUE, 0) is not a valid bound; you should write (10, MINVALUE, MINVALUE).

Also note that some element types, such as timestamp, have a notion of "infinity", which is just another value that can be stored. This is different from MINVALUE and MAXVALUE, which are not real values that can be stored, but rather they are ways of saying that the value is unbounded. MAXVALUE can be thought of as being greater than any other value, including "infinity" and MINVALUE as being less than any other value, including "minus infinity". Thus the range FROM ('infinity') TO (MAXVALUE) is not an empty range; it allows precisely one value to be stored — "infinity".

If DEFAULT is specified, the table will be created as the default partition of the parent table. This option is not available for hash-partitioned tables. A partition key value not fitting into any other partition of the given parent will be routed to the default partition.

When a table has an existing DEFAULT partition and a new partition is added to it, the default partition must be scanned to verify that it does not contain any rows which properly belong in the new partition. If the default partition contains a large number of rows, this may be slow. The scan will be skipped if the default partition is a foreign table or if it has a constraint which proves that it cannot contain rows which should be placed in the new partition.

When creating a hash partition, a modulus and remainder must be specified. The modulus must be a positive integer, and the remainder must be a non-negative integer less than the modulus. Typically, when initially setting up a hash-partitioned table, you should choose a modulus equal to the number of partitions and assign every table the same modulus and a different remainder (see examples, below). However, it is not required that every partition have the same modulus, only that every modulus which occurs among the partitions of a hash-partitioned table is a factor of the next larger modulus. This allows the number of partitions to be increased incrementally without needing to move all the data at once. For example, suppose you have a hash-partitioned table with 8 partitions, each of which has modulus 8, but find it necessary to increase the number of partitions to 16. You can detach one of the modulus-8 partitions, create two new modulus-16 partitions covering the same portion of the key space (one with a remainder equal to the remainder of the detached partition, and the other with a remainder equal to that value plus 8), and repopulate them with data. You can then repeat this -- perhaps at a later time -- for each modulus-8 partition until none remain. While this may still involve a large amount of data movement at each step, it is still better than having to create a whole new table and move all the data at once.

A partition must have the same column names and types as the partitioned table to which it belongs. Modifications to the column names or types of a partitioned table will automatically propagate to all partitions. CHECK constraints will be inherited automatically by every partition, but an individual partition may specify additional CHECK constraints; additional constraints with the same name and condition as in the parent will be merged with the parent constraint. Defaults may be specified separately for each partition. But note that a partition's default value is not applied when inserting a tuple through a partitioned table.

Rows inserted into a partitioned table will be automatically routed to the correct partition. If no suitable partition exists, an error will occur.

Operations such as TRUNCATE which normally affect a table and all of its inheritance children will cascade to all partitions, but may also be performed on an individual partition.

Note that creating a partition using PARTITION OF requires taking an ACCESS EXCLUSIVE lock on the parent partitioned table. Likewise, dropping a partition with DROP TABLE requires taking an ACCESS EXCLUSIVE lock on the parent table. It is possible to use ALTER TABLE ATTACH/DETACH PARTITION to perform these operations with a weaker lock, thus reducing interference with concurrent operations on the partitioned table.

LIKE source_table [ like_option ... ]

The LIKE clause specifies a table from which the new table automatically copies all column names, their data types, and their not-null constraints. Unlike INHERITS, the new table and original table are completely decoupled after creation is complete. Changes to the original table will not be applied to the new table, and it is not possible to include data of the new table in scans of the original table.

Also unlike INHERITS, columns and constraints copied by LIKE are not merged with similarly named columns and constraints. If the same name is specified explicitly or in another LIKE clause, an error is signaled.

The optional like_option clauses specify which additional properties of the original table to copy. Specifying INCLUDING copies the property, specifying EXCLUDING omits the property. EXCLUDING is the default. If multiple specifications are made for the same kind of object, the last one is used. The available options are:

INCLUDING COMMENTS

Comments for the copied columns, check constraints, indexes, and extended statistics will be copied. The default behavior is to exclude comments, resulting in the corresponding objects in the new table having no comments.

INCLUDING COMPRESSION

Compression method of the columns will be copied. The default behavior is to exclude compression methods, resulting in columns having the default compression method.

INCLUDING CONSTRAINTS

CHECK constraints will be copied. No distinction is made between column constraints and table constraints. Not-null constraints are always copied to the new table.

INCLUDING DEFAULTS

Default expressions for the copied column definitions will be copied. Otherwise, default expressions are not copied, resulting in the copied columns in the new table having null defaults. Note that copying defaults that call database-modification functions, such as nextval, may create a functional linkage between the original and new tables.

INCLUDING GENERATED

Any generation expressions of copied column definitions will be copied. By default, new columns will be regular base columns.

INCLUDING IDENTITY

Any identity specifications of copied column definitions will be copied. A new sequence is created for each identity column of the new table, separate from the sequences associated with the old table.

INCLUDING INDEXES

Indexes, PRIMARY KEY, UNIQUE, and EXCLUDE constraints on the original table will be created on the new table. Names for the new indexes and constraints are chosen according to the default rules, regardless of how the originals were named. (This behavior avoids possible duplicate-name failures for the new indexes.)

INCLUDING STATISTICS

Extended statistics are copied to the new table.

INCLUDING STORAGE

STORAGE settings for the copied column definitions will be copied. The default behavior is to exclude STORAGE settings, resulting in the copied columns in the new table having type-specific default settings. For more on STORAGE settings, see Section 65.2.

INCLUDING ALL

INCLUDING ALL is an abbreviated form selecting all the available individual options. (It could be useful to write individual EXCLUDING clauses after INCLUDING ALL to select all but some specific options.)

The LIKE clause can also be used to copy column definitions from views, foreign tables, or composite types. Inapplicable options (e.g., INCLUDING INDEXES from a view) are ignored.

CONSTRAINT constraint_name

An optional name for a column or table constraint. If the constraint is violated, the constraint name is present in error messages, so constraint names like col must be positive can be used to communicate helpful constraint information to client applications. (Double-quotes are needed to specify constraint names that contain spaces.) If a constraint name is not specified, the system generates a name.

NOT NULL

The column is not allowed to contain null values.

NULL

The column is allowed to contain null values. This is the default. This clause is only provided for compatibility with non-standard SQL databases. Its use is discouraged in new applications.

CHECK ( expression ) [ NO INHERIT ]

The CHECK clause specifies an expression producing a Boolean result which new or updated rows must satisfy for an insert or update operation to succeed. Expressions evaluating to TRUE or UNKNOWN succeed. Should any row of an insert or update operation produce a FALSE result, an error exception is raised and the insert or update does not alter the database. A check constraint specified as a column constraint should reference that column's value only, while an expression appearing in a table constraint can reference multiple columns. Currently, CHECK expressions cannot contain subqueries nor refer to variables other than columns of the current row (see Section 5.5.1). The system column tableoid may be referenced, but not any other system column.

A constraint marked with NO INHERIT will not propagate to child tables.

When a table has multiple CHECK constraints, they will be tested for each row in alphabetical order by name, after checking NOT NULL constraints. (PostgreSQL versions before 9.5 did not honor any particular firing order for CHECK constraints.)

DEFAULT default_expr

The DEFAULT clause assigns a default data value for the column whose column definition it appears within. The value is any variable-free expression (in particular, cross-references to other columns in the current table are not allowed). Subqueries are not allowed either. The data type of the default expression must match the data type of the column. The default expression will be used in any insert operation that does not specify a value for the column. If there is no default for a column, then the default is null.

GENERATED ALWAYS AS ( generation_expr ) STORED

This clause creates the column as a generated column. The column cannot be written to, and when read the result of the specified expression will be returned. The keyword STORED is required to signify that the column will be computed on write and will be stored on disk.

The generation expression can refer to other columns in the table, but not other generated columns. Any functions and operators used must be immutable. References to other tables are not allowed.

GENERATED { ALWAYS | BY DEFAULT } AS IDENTITY [ ( sequence_options ) ]

This clause creates the column as an identity column. It will have an implicit sequence attached to it and in newly-inserted rows the column will automatically have values from the sequence assigned to it. Such a column is implicitly NOT NULL. The clauses ALWAYS and BY DEFAULT determine how explicitly user-specified values are handled in INSERT and UPDATE commands.

In an INSERT command, if ALWAYS is selected, a user-specified value is only accepted if the INSERT statement specifies OVERRIDING SYSTEM VALUE. If BY DEFAULT is selected, then the user-specified value takes precedence. See INSERT(7) for details. (In the COPY command, user-specified values are always used regardless of this setting.)

In an UPDATE command, if ALWAYS is selected, any update of the column to any value other than DEFAULT will be rejected. If BY DEFAULT is selected, the column can be updated normally. (There is no OVERRIDING clause for the UPDATE command.)

The optional sequence_options clause can be used to override the parameters of the sequence. The available options include those shown for CREATE SEQUENCE (CREATE_SEQUENCE(7)), plus SEQUENCE NAME name, LOGGED, and UNLOGGED, which allow selection of the name and persistence level of the sequence. Without SEQUENCE NAME, the system chooses an unused name for the sequence. Without LOGGED or UNLOGGED, the sequence will have the same persistence level as the table.

UNIQUE [ NULLS [ NOT ] DISTINCT ] (column constraint)

UNIQUE [ NULLS [ NOT ] DISTINCT ] ( column_name [, ... ] ) [ INCLUDE ( column_name [, ...]) ] (table constraint)

The UNIQUE constraint specifies that a group of one or more columns of a table can contain only unique values. The behavior of a unique table constraint is the same as that of a unique column constraint, with the additional capability to span multiple columns. The constraint therefore enforces that any two rows must differ in at least one of these columns. For the purpose of a unique constraint, null values are not considered equal, unless NULLS NOT DISTINCT is specified.

Each unique constraint should name a set of columns that is different from the set of columns named by any other unique or primary key constraint defined for the table. (Otherwise, redundant unique constraints will be discarded.)

When establishing a unique constraint for a multi-level partition hierarchy, all the columns in the partition key of the target partitioned table, as well as those of all its descendant partitioned tables, must be included in the constraint definition.

Adding a unique constraint will automatically create a unique btree index on the column or group of columns used in the constraint. The created index has the same name as the unique constraint.

The optional INCLUDE clause adds to that index one or more columns that are simply “payload”: uniqueness is not enforced on them, and the index cannot be searched on the basis of those columns. However they can be retrieved by an index-only scan. Note that although the constraint is not enforced on included columns, it still depends on them. Consequently, some operations on such columns (e.g., DROP COLUMN) can cause cascaded constraint and index deletion.

PRIMARY KEY (column constraint)

PRIMARY KEY ( column_name [, ... ] ) [ INCLUDE ( column_name [, ...]) ] (table constraint)

The PRIMARY KEY constraint specifies that a column or columns of a table can contain only unique (non-duplicate), nonnull values. Only one primary key can be specified for a table, whether as a column constraint or a table constraint. The primary key constraint should name a set of columns that is different from the set of columns named by any unique constraint defined for the same table. (Otherwise, the unique constraint is redundant and will be discarded.)

PRIMARY KEY enforces the same data constraints as a combination of UNIQUE and NOT NULL. However, identifying a set of columns as the primary key also provides metadata about the design of the schema, since a primary key implies that other tables can rely on this set of columns as a unique identifier for rows.

When placed on a partitioned table, PRIMARY KEY constraints share the restrictions previously described for UNIQUE constraints.

Adding a PRIMARY KEY constraint will automatically create a unique btree index on the column or group of columns used in the constraint. That index has the same name as the primary key constraint.

The optional INCLUDE clause adds to that index one or more columns that are simply “payload”: uniqueness is not enforced on them, and the index cannot be searched on the basis of those columns. However they can be retrieved by an index-only scan. Note that although the constraint is not enforced on included columns, it still depends on them. Consequently, some operations on such columns (e.g., DROP COLUMN) can cause cascaded constraint and index deletion.

EXCLUDE [ USING index_method ] ( exclude_element WITH operator [, ... ] ) index_parameters [ WHERE ( predicate ) ]

The EXCLUDE clause defines an exclusion constraint, which guarantees that if any two rows are compared on the specified column(s) or expression(s) using the specified operator(s), not all of these comparisons will return TRUE. If all of the specified operators test for equality, this is equivalent to a UNIQUE constraint, although an ordinary unique constraint will be faster. However, exclusion constraints can specify constraints that are more general than simple equality. For example, you can specify a constraint that no two rows in the table contain overlapping circles (see Section 8.8) by using the && operator. The operator(s) are required to be commutative. Exclusion constraints are implemented using an index that has the same name as the constraint, so each specified operator must be associated with an appropriate operator class (see Section 11.10) for the index access method index_method. Each exclude_element defines a column of the index, so it can optionally specify a collation, an operator class, operator class parameters, and/or ordering options; these are described fully under CREATE INDEX (CREATE_INDEX(7)).

The access method must support amgettuple (see Chapter 62); at present this means GIN cannot be used. Although it's allowed, there is little point in using B-tree or hash indexes with an exclusion constraint, because this does nothing that an ordinary unique constraint doesn't do better. So in practice the access method will always be GiST or SP-GiST.

The predicate allows you to specify an exclusion constraint on a subset of the table; internally this creates a partial index. Note that parentheses are required around the predicate.

When establishing an exclusion constraint for a multi-level partition hierarchy, all the columns in the partition key of the target partitioned table, as well as those of all its descendant partitioned tables, must be included in the constraint definition. Additionally, those columns must be compared using the equality operator. These restrictions ensure that potentially-conflicting rows will exist in the same partition. The constraint may also refer to other columns which are not a part of any partition key, which can be compared using any appropriate operator.

REFERENCES reftable [ ( refcolumn ) ] [ MATCH matchtype ] [ ON DELETE referential_action ] [ ON UPDATE referential_action ] (column constraint)

FOREIGN KEY ( column_name [, ... ] ) REFERENCES reftable [ ( refcolumn [, ... ] ) ] [ MATCH matchtype ] [ ON DELETE referential_action ] [ ON UPDATE referential_action ] (table constraint)

These clauses specify a foreign key constraint, which requires that a group of one or more columns of the new table must only contain values that match values in the referenced column(s) of some row of the referenced table. If the refcolumn list is omitted, the primary key of the reftable is used. Otherwise, the refcolumn list must refer to the columns of a non-deferrable unique or primary key constraint or be the columns of a non-partial unique index. The user must have REFERENCES permission on the referenced table (either the whole table, or the specific referenced columns). The addition of a foreign key constraint requires a SHARE ROW EXCLUSIVE lock on the referenced table. Note that foreign key constraints cannot be defined between temporary tables and permanent tables. A value inserted into the referencing column(s) is matched against the values of the referenced table and referenced columns using the given match type. There are three match types: MATCH FULL, MATCH PARTIAL, and MATCH SIMPLE (which is the default). MATCH FULL will not allow one column of a multicolumn foreign key to be null unless all foreign key columns are null; if they are all null, the row is not required to have a match in the referenced table. MATCH SIMPLE allows any of the foreign key columns to be null; if any of them are null, the row is not required to have a match in the referenced table. MATCH PARTIAL is not yet implemented. (Of course, NOT NULL constraints can be applied to the referencing column(s) to prevent these cases from arising.)

In addition, when the data in the referenced columns is changed, certain actions are performed on the data in this table's columns. The ON DELETE clause specifies the action to perform when a referenced row in the referenced table is being deleted. Likewise, the ON UPDATE clause specifies the action to perform when a referenced column in the referenced table is being updated to a new value. If the row is updated, but the referenced column is not actually changed, no action is done. Referential actions other than the NO ACTION check cannot be deferred, even if the constraint is declared deferrable. There are the following possible actions for each clause:

NO ACTION

Produce an error indicating that the deletion or update would create a foreign key constraint violation. If the constraint is deferred, this error will be produced at constraint check time if there still exist any referencing rows. This is the default action.

RESTRICT

Produce an error indicating that the deletion or update would create a foreign key constraint violation. This is the same as NO ACTION except that the check is not deferrable.

CASCADE

Delete any rows referencing the deleted row, or update the values of the referencing column(s) to the new values of the referenced columns, respectively.

SET NULL [ ( column_name [, ... ] ) ]

Set all of the referencing columns, or a specified subset of the referencing columns, to null. A subset of columns can only be specified for ON DELETE actions.

SET DEFAULT [ ( column_name [, ... ] ) ]

Set all of the referencing columns, or a specified subset of the referencing columns, to their default values. A subset of columns can only be specified for ON DELETE actions. (There must be a row in the referenced table matching the default values, if they are not null, or the operation will fail.)

If the referenced column(s) are changed frequently, it might be wise to add an index to the referencing column(s) so that referential actions associated with the foreign key constraint can be performed more efficiently.

DEFERRABLE

NOT DEFERRABLE

This controls whether the constraint can be deferred. A constraint that is not deferrable will be checked immediately after every command. Checking of constraints that are deferrable can be postponed until the end of the transaction (using the SET CONSTRAINTS command). NOT DEFERRABLE is the default. Currently, only UNIQUE, PRIMARY KEY, EXCLUDE, and REFERENCES (foreign key) constraints accept this clause. NOT NULL and CHECK constraints are not deferrable. Note that deferrable constraints cannot be used as conflict arbiters in an INSERT statement that includes an ON CONFLICT clause.

INITIALLY IMMEDIATE

INITIALLY DEFERRED

If a constraint is deferrable, this clause specifies the default time to check the constraint. If the constraint is INITIALLY IMMEDIATE, it is checked after each statement. This is the default. If the constraint is INITIALLY DEFERRED, it is checked only at the end of the transaction. The constraint check time can be altered with the SET CONSTRAINTS command.

USING method

This optional clause specifies the table access method to use to store the contents for the new table; the method needs be an access method of type TABLE. See Chapter 61 for more information. If this option is not specified, the default table access method is chosen for the new table. See default_table_access_method for more information. When creating a partition, the table access method is the access method of its partitioned table, if set.

WITH ( storage_parameter [= value] [, ... ] )

This clause specifies optional storage parameters for a table or index; see Storage Parameters below for more information. For backward-compatibility the WITH clause for a table can also include OIDS=FALSE to specify that rows of the new table should not contain OIDs (object identifiers), OIDS=TRUE is not supported anymore.

WITHOUT OIDS

This is backward-compatible syntax for declaring a table WITHOUT OIDS, creating a table WITH OIDS is not supported anymore.

ON COMMIT

The behavior of temporary tables at the end of a transaction block can be controlled using ON COMMIT. The three options are: PRESERVE ROWS

No special action is taken at the ends of transactions. This is the default behavior.

DELETE ROWS

All rows in the temporary table will be deleted at the end of each transaction block. Essentially, an automatic TRUNCATE is done at each commit. When used on a partitioned table, this is not cascaded to its partitions.

DROP

The temporary table will be dropped at the end of the current transaction block. When used on a partitioned table, this action drops its partitions and when used on tables with inheritance children, it drops the dependent children.

TABLESPACE tablespace_name

The tablespace_name is the name of the tablespace in which the new table is to be created. If not specified, default_tablespace is consulted, or temp_tablespaces if the table is temporary. For partitioned tables, since no storage is required for the table itself, the tablespace specified overrides default_tablespace as the default tablespace to use for any newly created partitions when no other tablespace is explicitly specified.

USING INDEX TABLESPACE tablespace_name

This clause allows selection of the tablespace in which the index associated with a UNIQUE, PRIMARY KEY, or EXCLUDE constraint will be created. If not specified, default_tablespace is consulted, or temp_tablespaces if the table is temporary.

### Storage Parameters
The WITH clause can specify storage parameters for tables, and for indexes associated with a UNIQUE, PRIMARY KEY, or EXCLUDE constraint. Storage parameters for indexes are documented in CREATE INDEX (CREATE_INDEX(7)). The storage parameters currently available for tables are listed below. For many of these parameters, as shown, there is an additional parameter with the same name prefixed with toast., which controls the behavior of the table's secondary TOAST table, if any (see Section 65.2 for more information about TOAST). If a table parameter value is set and the equivalent toast. parameter is not, the TOAST table will use the table's parameter value. Specifying these parameters for partitioned tables is not supported, but you may specify them for individual leaf partitions.

fillfactor (integer)

The fillfactor for a table is a percentage between 10 and 100. 100 (complete packing) is the default. When a smaller fillfactor is specified, INSERT operations pack table pages only to the indicated percentage; the remaining space on each page is reserved for updating rows on that page. This gives UPDATE a chance to place the updated copy of a row on the same page as the original, which is more efficient than placing it on a different page, and makes heap-only tuple updates more likely. For a table whose entries are never updated, complete packing is the best choice, but in heavily updated tables smaller fillfactors are appropriate. This parameter cannot be set for TOAST tables.

toast_tuple_target (integer)

The toast_tuple_target specifies the minimum tuple length required before we try to compress and/or move long column values into TOAST tables, and is also the target length we try to reduce the length below once toasting begins. This affects columns marked as External (for move), Main (for compression), or Extended (for both) and applies only to new tuples. There is no effect on existing rows. By default this parameter is set to allow at least 4 tuples per block, which with the default block size will be 2040 bytes. Valid values are between 128 bytes and the (block size - header), by default 8160 bytes. Changing this value may not be useful for very short or very long rows. Note that the default setting is often close to optimal, and it is possible that setting this parameter could have negative effects in some cases. This parameter cannot be set for TOAST tables.

parallel_workers (integer)

This sets the number of workers that should be used to assist a parallel scan of this table. If not set, the system will determine a value based on the relation size. The actual number of workers chosen by the planner or by utility statements that use parallel scans may be less, for example due to the setting of max_worker_processes.

autovacuum_enabled, toast.autovacuum_enabled (boolean)

Enables or disables the autovacuum daemon for a particular table. If true, the autovacuum daemon will perform automatic VACUUM and/or ANALYZE operations on this table following the rules discussed in Section 24.1.6. If false, this table will not be autovacuumed, except to prevent transaction ID wraparound. See Section 24.1.5 for more about wraparound prevention. Note that the autovacuum daemon does not run at all (except to prevent transaction ID wraparound) if the autovacuum parameter is false; setting individual tables' storage parameters does not override that. Therefore there is seldom much point in explicitly setting this storage parameter to true, only to false.

vacuum_index_cleanup, toast.vacuum_index_cleanup (enum)

Forces or disables index cleanup when VACUUM is run on this table. The default value is AUTO. With OFF, index cleanup is disabled, with ON it is enabled, and with AUTO a decision is made dynamically, each time VACUUM runs. The dynamic behavior allows VACUUM to avoid needlessly scanning indexes to remove very few dead tuples. Forcibly disabling all index cleanup can speed up VACUUM very significantly, but may also lead to severely bloated indexes if table modifications are frequent. The INDEX_CLEANUP parameter of VACUUM, if specified, overrides the value of this option.

vacuum_truncate, toast.vacuum_truncate (boolean)

Enables or disables vacuum to try to truncate off any empty pages at the end of this table. The default value is true. If true, VACUUM and autovacuum do the truncation and the disk space for the truncated pages is returned to the operating system. Note that the truncation requires ACCESS EXCLUSIVE lock on the table. The TRUNCATE parameter of VACUUM, if specified, overrides the value of this option.

autovacuum_vacuum_threshold, toast.autovacuum_vacuum_threshold (integer)

Per-table value for autovacuum_vacuum_threshold parameter.

autovacuum_vacuum_scale_factor, toast.autovacuum_vacuum_scale_factor (floating point)

Per-table value for autovacuum_vacuum_scale_factor parameter.

autovacuum_vacuum_insert_threshold, toast.autovacuum_vacuum_insert_threshold (integer)

Per-table value for autovacuum_vacuum_insert_threshold parameter. The special value of -1 may be used to disable insert vacuums on the table.

autovacuum_vacuum_insert_scale_factor, toast.autovacuum_vacuum_insert_scale_factor (floating point)

Per-table value for autovacuum_vacuum_insert_scale_factor parameter.

autovacuum_analyze_threshold (integer)

Per-table value for autovacuum_analyze_threshold parameter.

autovacuum_analyze_scale_factor (floating point)

Per-table value for autovacuum_analyze_scale_factor parameter.

autovacuum_vacuum_cost_delay, toast.autovacuum_vacuum_cost_delay (floating point)

Per-table value for autovacuum_vacuum_cost_delay parameter.

autovacuum_vacuum_cost_limit, toast.autovacuum_vacuum_cost_limit (integer)

Per-table value for autovacuum_vacuum_cost_limit parameter.

autovacuum_freeze_min_age, toast.autovacuum_freeze_min_age (integer)

Per-table value for vacuum_freeze_min_age parameter. Note that autovacuum will ignore per-table autovacuum_freeze_min_age parameters that are larger than half the system-wide autovacuum_freeze_max_age setting.

autovacuum_freeze_max_age, toast.autovacuum_freeze_max_age (integer)

Per-table value for autovacuum_freeze_max_age parameter. Note that autovacuum will ignore per-table autovacuum_freeze_max_age parameters that are larger than the system-wide setting (it can only be set smaller).

autovacuum_freeze_table_age, toast.autovacuum_freeze_table_age (integer)

Per-table value for vacuum_freeze_table_age parameter.

autovacuum_multixact_freeze_min_age, toast.autovacuum_multixact_freeze_min_age (integer)

Per-table value for vacuum_multixact_freeze_min_age parameter. Note that autovacuum will ignore per-table autovacuum_multixact_freeze_min_age parameters that are larger than half the system-wide autovacuum_multixact_freeze_max_age setting.

autovacuum_multixact_freeze_max_age, toast.autovacuum_multixact_freeze_max_age (integer)

Per-table value for autovacuum_multixact_freeze_max_age parameter. Note that autovacuum will ignore per-table autovacuum_multixact_freeze_max_age parameters that are larger than the system-wide setting (it can only be set smaller).

autovacuum_multixact_freeze_table_age, toast.autovacuum_multixact_freeze_table_age (integer)

Per-table value for vacuum_multixact_freeze_table_age parameter.

log_autovacuum_min_duration, toast.log_autovacuum_min_duration (integer)

Per-table value for log_autovacuum_min_duration parameter.

user_catalog_table (boolean)

Declare the table as an additional catalog table for purposes of logical replication. See Section 47.6.2 for details. This parameter cannot be set for TOAST tables.

## NOTES
PostgreSQL automatically creates an index for each unique constraint and primary key constraint to enforce uniqueness. Thus, it is not necessary to create an index explicitly for primary key columns. (See CREATE INDEX (CREATE_INDEX(7)) for more information.)

Unique constraints and primary keys are not inherited in the current implementation. This makes the combination of inheritance and unique constraints rather dysfunctional.

A table cannot have more than 1600 columns. (In practice, the effective limit is usually lower because of tuple-length constraints.)

## EXAMPLES
Create table films and table distributors:

```
CREATE TABLE films (

    code        char(5) CONSTRAINT firstkey PRIMARY KEY,

    title       varchar(40) NOT NULL,

    did         integer NOT NULL,

    date_prod   date,

    kind        varchar(10),

    len         interval hour to minute
);
CREATE TABLE distributors (

     did    integer PRIMARY KEY GENERATED BY DEFAULT AS IDENTITY,

     name   varchar(40) NOT NULL CHECK (name <> '')
);
```

Create a table with a 2-dimensional array:

```
CREATE TABLE array_int (

    vector  int[][]
);
```

Define a unique table constraint for the table films. Unique table constraints can be defined on one or more columns of the table:

```
CREATE TABLE films (

    code        char(5),

    title       varchar(40),

    did         integer,

    date_prod   date,

    kind        varchar(10),

    len         interval hour to minute,

    CONSTRAINT production UNIQUE(date_prod)
);
```

Define a check column constraint:

```
CREATE TABLE distributors (

    did     integer CHECK (did > 100),

    name    varchar(40)
);
```

Define a check table constraint:

```
CREATE TABLE distributors (

    did     integer,

    name    varchar(40),

    CONSTRAINT con1 CHECK (did > 100 AND name <> '')
);
```

Define a primary key table constraint for the table films:

```
CREATE TABLE films (

    code        char(5),

    title       varchar(40),

    did         integer,

    date_prod   date,

    kind        varchar(10),

    len         interval hour to minute,

    CONSTRAINT code_title PRIMARY KEY(code,title)
);
```

Define a primary key constraint for table distributors. The following two examples are equivalent, the first using the table constraint syntax, the second the column constraint syntax:

```
CREATE TABLE distributors (

    did     integer,

    name    varchar(40),

    PRIMARY KEY(did)
);
CREATE TABLE distributors (

    did     integer PRIMARY KEY,

    name    varchar(40)
);
```

Assign a literal constant default value for the column name, arrange for the default value of column did to be generated by selecting the next value of a sequence object, and make the default value of modtime be the time at which the row is inserted:

```
CREATE TABLE distributors (

    name      varchar(40) DEFAULT 'Luso Films',

    did       integer DEFAULT nextval('distributors_serial'),

    modtime   timestamp DEFAULT current_timestamp
);
```

Define two NOT NULL column constraints on the table distributors, one of which is explicitly given a name:

```
CREATE TABLE distributors (

    did     integer CONSTRAINT no_null NOT NULL,

    name    varchar(40) NOT NULL
);
```

Define a unique constraint for the name column:

```
CREATE TABLE distributors (

    did     integer,

    name    varchar(40) UNIQUE
);
```

The same, specified as a table constraint:

```
CREATE TABLE distributors (

    did     integer,

    name    varchar(40),

    UNIQUE(name)
);
```

Create the same table, specifying 70% fill factor for both the table and its unique index:

```
CREATE TABLE distributors (

    did     integer,

    name    varchar(40),

    UNIQUE(name) WITH (fillfactor=70)
)
WITH (fillfactor=70);
```

Create table circles with an exclusion constraint that prevents any two circles from overlapping:

```
CREATE TABLE circles (

    c circle,

    EXCLUDE USING gist (c WITH &&)
);
```

Create table cinemas in tablespace diskvol1:

```
CREATE TABLE cinemas (

        id serial,

        name text,

        location text
) TABLESPACE diskvol1;
```

Create a composite type and a typed table:

```
CREATE TYPE employee_type AS (name text, salary numeric);
CREATE TABLE employees OF employee_type (

    PRIMARY KEY (name),

    salary WITH OPTIONS DEFAULT 1000
);
```

Create a range partitioned table:

```
CREATE TABLE measurement (

    logdate         date not null,

    peaktemp        int,

    unitsales       int
) PARTITION BY RANGE (logdate);
```

Create a range partitioned table with multiple columns in the partition key:

```
CREATE TABLE measurement_year_month (

    logdate         date not null,

    peaktemp        int,

    unitsales       int
) PARTITION BY RANGE (EXTRACT(YEAR FROM logdate), EXTRACT(MONTH FROM logdate));
```

Create a list partitioned table:

```
CREATE TABLE cities (

    city_id      bigserial not null,

    name         text not null,

    population   bigint
) PARTITION BY LIST (left(lower(name), 1));
```

Create a hash partitioned table:

```
CREATE TABLE orders (

    order_id     bigint not null,

    cust_id      bigint not null,

    status       text
) PARTITION BY HASH (order_id);
```

Create partition of a range partitioned table:

```
CREATE TABLE measurement_y2016m07

    PARTITION OF measurement (

    unitsales DEFAULT 0
) FOR VALUES FROM ('2016-07-01') TO ('2016-08-01');
```

Create a few partitions of a range partitioned table with multiple columns in the partition key:

```
CREATE TABLE measurement_ym_older

    PARTITION OF measurement_year_month

    FOR VALUES FROM (MINVALUE, MINVALUE) TO (2016, 11);
CREATE TABLE measurement_ym_y2016m11

    PARTITION OF measurement_year_month

    FOR VALUES FROM (2016, 11) TO (2016, 12);
CREATE TABLE measurement_ym_y2016m12

    PARTITION OF measurement_year_month

    FOR VALUES FROM (2016, 12) TO (2017, 01);
CREATE TABLE measurement_ym_y2017m01

    PARTITION OF measurement_year_month

    FOR VALUES FROM (2017, 01) TO (2017, 02);
```

Create partition of a list partitioned table:

```
CREATE TABLE cities_ab

    PARTITION OF cities (

    CONSTRAINT city_id_nonzero CHECK (city_id != 0)
) FOR VALUES IN ('a', 'b');
```

Create partition of a list partitioned table that is itself further partitioned and then add a partition to it:

```
CREATE TABLE cities_ab

    PARTITION OF cities (

    CONSTRAINT city_id_nonzero CHECK (city_id != 0)
) FOR VALUES IN ('a', 'b') PARTITION BY RANGE (population);
CREATE TABLE cities_ab_10000_to_100000

    PARTITION OF cities_ab FOR VALUES FROM (10000) TO (100000);
```

Create partitions of a hash partitioned table:

```
CREATE TABLE orders_p1 PARTITION OF orders

    FOR VALUES WITH (MODULUS 4, REMAINDER 0);
CREATE TABLE orders_p2 PARTITION OF orders

    FOR VALUES WITH (MODULUS 4, REMAINDER 1);
CREATE TABLE orders_p3 PARTITION OF orders

    FOR VALUES WITH (MODULUS 4, REMAINDER 2);
CREATE TABLE orders_p4 PARTITION OF orders

    FOR VALUES WITH (MODULUS 4, REMAINDER 3);
```

Create a default partition:

```
CREATE TABLE cities_partdef

    PARTITION OF cities DEFAULT;
```

## COMPATIBILITY
The CREATE TABLE command conforms to the SQL standard, with exceptions listed below.

### Temporary Tables
Although the syntax of CREATE TEMPORARY TABLE resembles that of the SQL standard, the effect is not the same. In the standard, temporary tables are defined just once and automatically exist (starting with empty contents) in every session that needs them. PostgreSQL instead requires each session to issue its own CREATE TEMPORARY TABLE command for each temporary table to be used. This allows different sessions to use the same temporary table name for different purposes, whereas the standard's approach constrains all instances of a given temporary table name to have the same table structure.

The standard's definition of the behavior of temporary tables is widely ignored. PostgreSQL's behavior on this point is similar to that of several other SQL databases.

The SQL standard also distinguishes between global and local temporary tables, where a local temporary table has a separate set of contents for each SQL module within each session, though its definition is still shared across sessions. Since PostgreSQL does not support SQL modules, this distinction is not relevant in PostgreSQL.

For compatibility's sake, PostgreSQL will accept the GLOBAL and LOCAL keywords in a temporary table declaration, but they currently have no effect. Use of these keywords is discouraged, since future versions of PostgreSQL might adopt a more standard-compliant interpretation of their meaning.

The ON COMMIT clause for temporary tables also resembles the SQL standard, but has some differences. If the ON COMMIT clause is omitted, SQL specifies that the default behavior is ON COMMIT DELETE ROWS. However, the default behavior in PostgreSQL is ON COMMIT PRESERVE ROWS. The ON COMMIT DROP option does not exist in SQL.

### Non-Deferred Uniqueness Constraints
When a UNIQUE or PRIMARY KEY constraint is not deferrable, PostgreSQL checks for uniqueness immediately whenever a row is inserted or modified. The SQL standard says that uniqueness should be enforced only at the end of the statement; this makes a difference when, for example, a single command updates multiple key values. To obtain standard-compliant behavior, declare the constraint as DEFERRABLE but not deferred (i.e., INITIALLY IMMEDIATE). Be aware that this can be significantly slower than immediate uniqueness checking.

### Column Check Constraints
The SQL standard says that CHECK column constraints can only refer to the column they apply to; only CHECK table constraints can refer to multiple columns. PostgreSQL does not enforce this restriction; it treats column and table check constraints alike.

### EXCLUDE Constraint
The EXCLUDE constraint type is a PostgreSQL extension.

### Foreign Key Constraints
The ability to specify column lists in the foreign key actions SET DEFAULT and SET NULL is a PostgreSQL extension.

It is a PostgreSQL extension that a foreign key constraint may reference columns of a unique index instead of columns of a primary key or unique constraint.

### NULL “Constraint”
The NULL “constraint” (actually a non-constraint) is a PostgreSQL extension to the SQL standard that is included for compatibility with some other database systems (and for symmetry with the NOT NULL constraint). Since it is the default for any column, its presence is simply noise.

### Constraint Naming
The SQL standard says that table and domain constraints must have names that are unique across the schema containing the table or domain. PostgreSQL is laxer: it only requires constraint names to be unique across the constraints attached to a particular table or domain. However, this extra freedom does not exist for index-based constraints (UNIQUE, PRIMARY KEY, and EXCLUDE constraints), because the associated index is named the same as the constraint, and index names must be unique across all relations within the same schema.

Currently, PostgreSQL does not record names for not-null constraints at all, so they are not subject to the uniqueness restriction. This might change in a future release.

### Inheritance
Multiple inheritance via the INHERITS clause is a PostgreSQL language extension. SQL:1999 and later define single inheritance using a different syntax and different semantics. SQL:1999-style inheritance is not yet supported by PostgreSQL.

### Zero-Column Tables
PostgreSQL allows a table of no columns to be created (for example, CREATE TABLE foo();). This is an extension from the SQL standard, which does not allow zero-column tables. Zero-column tables are not in themselves very useful, but disallowing them creates odd special cases for ALTER TABLE DROP COLUMN, so it seems cleaner to ignore this spec restriction.

### Multiple Identity Columns
PostgreSQL allows a table to have more than one identity column. The standard specifies that a table can have at most one identity column. This is relaxed mainly to give more flexibility for doing schema changes or migrations. Note that the INSERT command supports only one override clause that applies to the entire statement, so having multiple identity columns with different behaviors is not well supported.

### Generated Columns
The option STORED is not standard but is also used by other SQL implementations. The SQL standard does not specify the storage of generated columns.

### LIKE Clause
While a LIKE clause exists in the SQL standard, many of the options that PostgreSQL accepts for it are not in the standard, and some of the standard's options are not implemented by PostgreSQL.

### WITH Clause
The WITH clause is a PostgreSQL extension; storage parameters are not in the standard.

### Tablespaces
The PostgreSQL concept of tablespaces is not part of the standard. Hence, the clauses TABLESPACE and USING INDEX TABLESPACE are extensions.

### Typed Tables
Typed tables implement a subset of the SQL standard. According to the standard, a typed table has columns corresponding to the underlying composite type as well as one other column that is the “self-referencing column”. PostgreSQL does not support self-referencing columns explicitly.

### PARTITION BY Clause
The PARTITION BY clause is a PostgreSQL extension.

### PARTITION OF Clause
The PARTITION OF clause is a PostgreSQL extension.

## SEE ALSO
ALTER TABLE (ALTER_TABLE(7)), DROP TABLE (DROP_TABLE(7)), CREATE TABLE AS (CREATE_TABLE_AS(7)), CREATE TABLESPACE (CREATE_TABLESPACE(7)), CREATE TYPE (CREATE_TYPE(7))

branch: sisyphus


title: CREATE_TABLESPACE(7)

summary: define a new tablespace

text:
# CREATE_TABLESPACE(7)

## NAME
CREATE_TABLESPACE - define a new tablespace

## SYNOPSIS

```
CREATE TABLESPACE tablespace_name

    [ OWNER { new_owner | CURRENT_ROLE | CURRENT_USER | SESSION_USER } ]

    LOCATION 'directory'

    [ WITH ( tablespace_option = value [, ... ] ) ]
```

## DESCRIPTION
CREATE TABLESPACE registers a new cluster-wide tablespace. The tablespace name must be distinct from the name of any existing tablespace in the database cluster.

A tablespace allows superusers to define an alternative location on the file system where the data files containing database objects (such as tables and indexes) can reside.

A user with appropriate privileges can pass tablespace_name to CREATE DATABASE, CREATE TABLE, CREATE INDEX or ADD CONSTRAINT to have the data files for these objects stored within the specified tablespace.

Warning

A tablespace cannot be used independently of the cluster in which it is defined; see Section 22.6.

## PARAMETERS
tablespace_name

The name of a tablespace to be created. The name cannot begin with pg_, as such names are reserved for system tablespaces.

user_name

The name of the user who will own the tablespace. If omitted, defaults to the user executing the command. Only superusers can create tablespaces, but they can assign ownership of tablespaces to non-superusers.

directory

The directory that will be used for the tablespace. The directory must exist (CREATE TABLESPACE will not create it), should be empty, and must be owned by the PostgreSQL system user. The directory must be specified by an absolute path name.

tablespace_option

A tablespace parameter to be set or reset. Currently, the only available parameters are seq_page_cost, random_page_cost, effective_io_concurrency and maintenance_io_concurrency. Setting these values for a particular tablespace will override the planner's usual estimate of the cost of reading pages from tables in that tablespace, and the executor's prefetching behavior, as established by the configuration parameters of the same name (see seq_page_cost, random_page_cost, effective_io_concurrency, maintenance_io_concurrency). This may be useful if one tablespace is located on a disk which is faster or slower than the remainder of the I/O subsystem.

## NOTES
CREATE TABLESPACE cannot be executed inside a transaction block.

## EXAMPLES
To create a tablespace dbspace at file system location /data/dbs, first create the directory using operating system facilities and set the correct ownership:

```
mkdir /data/dbs
chown postgres:postgres /data/dbs
```

Then issue the tablespace creation command inside PostgreSQL:

```
CREATE TABLESPACE dbspace LOCATION '/data/dbs';
```

To create a tablespace owned by a different database user, use a command like this:

```
CREATE TABLESPACE indexspace OWNER genevieve LOCATION '/data/indexes';
```

## COMPATIBILITY
CREATE TABLESPACE is a PostgreSQL extension.

## SEE ALSO
CREATE DATABASE (CREATE_DATABASE(7)), CREATE TABLE (CREATE_TABLE(7)), CREATE INDEX (CREATE_INDEX(7)), DROP TABLESPACE (DROP_TABLESPACE(7)), ALTER TABLESPACE (ALTER_TABLESPACE(7))


title: CREATE_TABLE_AS(7)

text:
# CREATE_TABLE_AS(7)

## NAME
CREATE_TABLE_AS - define a new table from the results of a query

## SYNOPSIS

```
CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE [ IF NOT EXISTS ] table_name

    [ (column_name [, ...] ) ]

    [ USING method ]

    [ WITH ( storage_parameter [= value] [, ... ] ) | WITHOUT OIDS ]

    [ ON COMMIT { PRESERVE ROWS | DELETE ROWS | DROP } ]

    [ TABLESPACE tablespace_name ]

    AS query

    [ WITH [ NO ] DATA ]
```

## DESCRIPTION
CREATE TABLE AS creates a table and fills it with data computed by a SELECT command. The table columns have the names and data types associated with the output columns of the SELECT (except that you can override the column names by giving an explicit list of new column names).

CREATE TABLE AS bears some resemblance to creating a view, but it is really quite different: it creates a new table and evaluates the query just once to fill the new table initially. The new table will not track subsequent changes to the source tables of the query. In contrast, a view re-evaluates its defining SELECT statement whenever it is queried.

CREATE TABLE AS requires CREATE privilege on the schema used for the table.

## PARAMETERS
GLOBAL or LOCAL

Ignored for compatibility. Use of these keywords is deprecated; refer to CREATE TABLE (CREATE_TABLE(7)) for details.

TEMPORARY or TEMP

If specified, the table is created as a temporary table. Refer to CREATE TABLE (CREATE_TABLE(7)) for details.

UNLOGGED

If specified, the table is created as an unlogged table. Refer to CREATE TABLE (CREATE_TABLE(7)) for details.

IF NOT EXISTS

Do not throw an error if a relation with the same name already exists; simply issue a notice and leave the table unmodified.

table_name

The name (optionally schema-qualified) of the table to be created.

column_name

The name of a column in the new table. If column names are not provided, they are taken from the output column names of the query.

USING method

This optional clause specifies the table access method to use to store the contents for the new table; the method needs be an access method of type TABLE. See Chapter 61 for more information. If this option is not specified, the default table access method is chosen for the new table. See default_table_access_method for more information.

WITH ( storage_parameter [= value] [, ... ] )

This clause specifies optional storage parameters for the new table; see Storage Parameters in the CREATE TABLE (CREATE_TABLE(7)) documentation for more information. For backward-compatibility the WITH clause for a table can also include OIDS=FALSE to specify that rows of the new table should contain no OIDs (object identifiers), OIDS=TRUE is not supported anymore.

WITHOUT OIDS

This is backward-compatible syntax for declaring a table WITHOUT OIDS, creating a table WITH OIDS is not supported anymore.

ON COMMIT

The behavior of temporary tables at the end of a transaction block can be controlled using ON COMMIT. The three options are: PRESERVE ROWS

No special action is taken at the ends of transactions. This is the default behavior.

DELETE ROWS

All rows in the temporary table will be deleted at the end of each transaction block. Essentially, an automatic TRUNCATE is done at each commit.

DROP

The temporary table will be dropped at the end of the current transaction block.

TABLESPACE tablespace_name

The tablespace_name is the name of the tablespace in which the new table is to be created. If not specified, default_tablespace is consulted, or temp_tablespaces if the table is temporary.

query

A SELECT, TABLE, or VALUES command, or an EXECUTE command that runs a prepared SELECT, TABLE, or VALUES query.

WITH [ NO ] DATA

This clause specifies whether or not the data produced by the query should be copied into the new table. If not, only the table structure is copied. The default is to copy the data.

## NOTES
This command is functionally similar to SELECT INTO (SELECT_INTO(7)), but it is preferred since it is less likely to be confused with other uses of the SELECT INTO syntax. Furthermore, CREATE TABLE AS offers a superset of the functionality offered by SELECT INTO.

## EXAMPLES
Create a new table films_recent consisting of only recent entries from the table films:

```
CREATE TABLE films_recent AS

  SELECT * FROM films WHERE date_prod >= '2002-01-01';
```

To copy a table completely, the short form using the TABLE command can also be used:

```
CREATE TABLE films2 AS

  TABLE films;
```

Create a new temporary table films_recent, consisting of only recent entries from the table films, using a prepared statement. The new table will be dropped at commit:

```
PREPARE recentfilms(date) AS

  SELECT * FROM films WHERE date_prod > $1;
CREATE TEMP TABLE films_recent ON COMMIT DROP AS

  EXECUTE recentfilms('2002-01-01');
```

## COMPATIBILITY
CREATE TABLE AS conforms to the SQL standard. The following are nonstandard extensions:

•The standard requires parentheses around the subquery clause; in PostgreSQL, these parentheses are optional.

•In the standard, the WITH [ NO ] DATA clause is required; in PostgreSQL it is optional.

•PostgreSQL handles temporary tables in a way rather different from the standard; see CREATE TABLE (CREATE_TABLE(7)) for details.

•The WITH clause is a PostgreSQL extension; storage parameters are not in the standard.

•The PostgreSQL concept of tablespaces is not part of the standard. Hence, the clause TABLESPACE is an extension.

## SEE ALSO
CREATE MATERIALIZED VIEW (CREATE_MATERIALIZED_VIEW(7)), CREATE TABLE (CREATE_TABLE(7)), EXECUTE(7), SELECT(7), SELECT INTO (SELECT_INTO(7)), VALUES(7)


title: CREATE_TEXT_SEARCH_CONFIGURATION(7)

summary: define a new text search configuration

text:
# CREATE_TEXT_SEARCH_CONFIGURATION(7)

## NAME
CREATE_TEXT_SEARCH_CONFIGURATION - define a new text search configuration

## SYNOPSIS

```
CREATE TEXT SEARCH CONFIGURATION name (

    PARSER = parser_name |

    COPY = source_config
)
```

## DESCRIPTION
CREATE TEXT SEARCH CONFIGURATION creates a new text search configuration. A text search configuration specifies a text search parser that can divide a string into tokens, plus dictionaries that can be used to determine which tokens are of interest for searching.

If only the parser is specified, then the new text search configuration initially has no mappings from token types to dictionaries, and therefore will ignore all words. Subsequent ALTER TEXT SEARCH CONFIGURATION commands must be used to create mappings to make the configuration useful. Alternatively, an existing text search configuration can be copied.

If a schema name is given then the text search configuration is created in the specified schema. Otherwise it is created in the current schema.

The user who defines a text search configuration becomes its owner.

Refer to Chapter 12 for further information.

## PARAMETERS
name

The name of the text search configuration to be created. The name can be schema-qualified.

parser_name

The name of the text search parser to use for this configuration.

source_config

The name of an existing text search configuration to copy.

## NOTES
The PARSER and COPY options are mutually exclusive, because when an existing configuration is copied, its parser selection is copied too.

## COMPATIBILITY
There is no CREATE TEXT SEARCH CONFIGURATION statement in the SQL standard.

## SEE ALSO
ALTER TEXT SEARCH CONFIGURATION (ALTER_TEXT_SEARCH_CONFIGURATION(7)), DROP TEXT SEARCH CONFIGURATION (DROP_TEXT_SEARCH_CONFIGURATION(7))


title: CREATE_TEXT_SEARCH_DICTIONARY(7)

summary: define a new text search dictionary

text:
# CREATE_TEXT_SEARCH_DICTIONARY(7)

## NAME
CREATE_TEXT_SEARCH_DICTIONARY - define a new text search dictionary

## SYNOPSIS

```
CREATE TEXT SEARCH DICTIONARY name (

    TEMPLATE = template

    [, option = value [, ... ]]
)
```

## DESCRIPTION
CREATE TEXT SEARCH DICTIONARY creates a new text search dictionary. A text search dictionary specifies a way of recognizing interesting or uninteresting words for searching. A dictionary depends on a text search template, which specifies the functions that actually perform the work. Typically the dictionary provides some options that control the detailed behavior of the template's functions.

If a schema name is given then the text search dictionary is created in the specified schema. Otherwise it is created in the current schema.

The user who defines a text search dictionary becomes its owner.

Refer to Chapter 12 for further information.

## PARAMETERS
name

The name of the text search dictionary to be created. The name can be schema-qualified.

template

The name of the text search template that will define the basic behavior of this dictionary.

option

The name of a template-specific option to be set for this dictionary.

value

The value to use for a template-specific option. If the value is not a simple identifier or number, it must be quoted (but you can always quote it, if you wish).

The options can appear in any order.

## EXAMPLES
The following example command creates a Snowball-based dictionary with a nonstandard list of stop words.

```
CREATE TEXT SEARCH DICTIONARY my_russian (

    template = snowball,

    language = russian,

    stopwords = myrussian
);
```

## COMPATIBILITY
There is no CREATE TEXT SEARCH DICTIONARY statement in the SQL standard.

## SEE ALSO
ALTER TEXT SEARCH DICTIONARY (ALTER_TEXT_SEARCH_DICTIONARY(7)), DROP TEXT SEARCH DICTIONARY (DROP_TEXT_SEARCH_DICTIONARY(7))


title: CREATE_TEXT_SEARCH_PARSER(7)

summary: define a new text search parser

text:
# CREATE_TEXT_SEARCH_PARSER(7)

## NAME
CREATE_TEXT_SEARCH_PARSER - define a new text search parser

## SYNOPSIS

```
CREATE TEXT SEARCH PARSER name (

    START = start_function ,

    GETTOKEN = gettoken_function ,

    END = end_function ,

    LEXTYPES = lextypes_function

    [, HEADLINE = headline_function ]
)
```

## DESCRIPTION
CREATE TEXT SEARCH PARSER creates a new text search parser. A text search parser defines a method for splitting a text string into tokens and assigning types (categories) to the tokens. A parser is not particularly useful by itself, but must be bound into a text search configuration along with some text search dictionaries to be used for searching.

If a schema name is given then the text search parser is created in the specified schema. Otherwise it is created in the current schema.

You must be a superuser to use CREATE TEXT SEARCH PARSER. (This restriction is made because an erroneous text search parser definition could confuse or even crash the server.)

Refer to Chapter 12 for further information.

## PARAMETERS
name

The name of the text search parser to be created. The name can be schema-qualified.

start_function

The name of the start function for the parser.

gettoken_function

The name of the get-next-token function for the parser.

end_function

The name of the end function for the parser.

lextypes_function

The name of the lextypes function for the parser (a function that returns information about the set of token types it produces).

headline_function

The name of the headline function for the parser (a function that summarizes a set of tokens).

The function names can be schema-qualified if necessary. Argument types are not given, since the argument list for each type of function is predetermined. All except the headline function are required.

The arguments can appear in any order, not only the one shown above.

## COMPATIBILITY
There is no CREATE TEXT SEARCH PARSER statement in the SQL standard.

## SEE ALSO
ALTER TEXT SEARCH PARSER (ALTER_TEXT_SEARCH_PARSER(7)), DROP TEXT SEARCH PARSER (DROP_TEXT_SEARCH_PARSER(7))


title: CREATE_TEXT_SEARCH_TEMPLATE(7)

summary: define a new text search template

text:
# CREATE_TEXT_SEARCH_TEMPLATE(7)

## NAME
CREATE_TEXT_SEARCH_TEMPLATE - define a new text search template

## SYNOPSIS

```
CREATE TEXT SEARCH TEMPLATE name (

    [ INIT = init_function , ]

    LEXIZE = lexize_function
)
```

## DESCRIPTION
CREATE TEXT SEARCH TEMPLATE creates a new text search template. Text search templates define the functions that implement text search dictionaries. A template is not useful by itself, but must be instantiated as a dictionary to be used. The dictionary typically specifies parameters to be given to the template functions.

If a schema name is given then the text search template is created in the specified schema. Otherwise it is created in the current schema.

You must be a superuser to use CREATE TEXT SEARCH TEMPLATE. This restriction is made because an erroneous text search template definition could confuse or even crash the server. The reason for separating templates from dictionaries is that a template encapsulates the “unsafe” aspects of defining a dictionary. The parameters that can be set when defining a dictionary are safe for unprivileged users to set, and so creating a dictionary need not be a privileged operation.

Refer to Chapter 12 for further information.

## PARAMETERS
name

The name of the text search template to be created. The name can be schema-qualified.

init_function

The name of the init function for the template.

lexize_function

The name of the lexize function for the template.

The function names can be schema-qualified if necessary. Argument types are not given, since the argument list for each type of function is predetermined. The lexize function is required, but the init function is optional.

The arguments can appear in any order, not only the one shown above.

## COMPATIBILITY
There is no CREATE TEXT SEARCH TEMPLATE statement in the SQL standard.

## SEE ALSO
ALTER TEXT SEARCH TEMPLATE (ALTER_TEXT_SEARCH_TEMPLATE(7)), DROP TEXT SEARCH TEMPLATE (DROP_TEXT_SEARCH_TEMPLATE(7))


title: CREATE_TRANSFORM(7)

summary: define a new transform

text:
# CREATE_TRANSFORM(7)

## NAME
CREATE_TRANSFORM - define a new transform

## SYNOPSIS

```
CREATE [ OR REPLACE ] TRANSFORM FOR type_name LANGUAGE lang_name (

    FROM SQL WITH FUNCTION from_sql_function_name [ (argument_type [, ...]) ],

    TO SQL WITH FUNCTION to_sql_function_name [ (argument_type [, ...]) ]
);
```

## DESCRIPTION
CREATE TRANSFORM defines a new transform. CREATE OR REPLACE TRANSFORM will either create a new transform, or replace an existing definition.

A transform specifies how to adapt a data type to a procedural language. For example, when writing a function in PL/Python using the hstore type, PL/Python has no prior knowledge how to present hstore values in the Python environment. Language implementations usually default to using the text representation, but that is inconvenient when, for example, an associative array or a list would be more appropriate.

A transform specifies two functions:

•A “from SQL” function that converts the type from the SQL environment to the language. This function will be invoked on the arguments of a function written in the language.

•A “to SQL” function that converts the type from the language to the SQL environment. This function will be invoked on the return value of a function written in the language.

It is not necessary to provide both of these functions. If one is not specified, the language-specific default behavior will be used if necessary. (To prevent a transformation in a certain direction from happening at all, you could also write a transform function that always errors out.)

To be able to create a transform, you must own and have USAGE privilege on the type, have USAGE privilege on the language, and own and have EXECUTE privilege on the from-SQL and to-SQL functions, if specified.

## PARAMETERS
type_name

The name of the data type of the transform.

lang_name

The name of the language of the transform.

from_sql_function_name[(argument_type [, ...])]

The name of the function for converting the type from the SQL environment to the language. It must take one argument of type internal and return type internal. The actual argument will be of the type for the transform, and the function should be coded as if it were. (But it is not allowed to declare an SQL-level function returning internal without at least one argument of type internal.) The actual return value will be something specific to the language implementation. If no argument list is specified, the function name must be unique in its schema.

to_sql_function_name[(argument_type [, ...])]

The name of the function for converting the type from the language to the SQL environment. It must take one argument of type internal and return the type that is the type for the transform. The actual argument value will be something specific to the language implementation. If no argument list is specified, the function name must be unique in its schema.

## NOTES
Use DROP TRANSFORM to remove transforms.

## EXAMPLES
To create a transform for type hstore and language plpython3u, first set up the type and the language:

```
CREATE TYPE hstore ...;
CREATE EXTENSION plpython3u;
```

Then create the necessary functions:

```
CREATE FUNCTION hstore_to_plpython(val internal) RETURNS internal
LANGUAGE C STRICT IMMUTABLE
AS ...;
CREATE FUNCTION plpython_to_hstore(val internal) RETURNS hstore
LANGUAGE C STRICT IMMUTABLE
AS ...;
```

And finally create the transform to connect them all together:

```
CREATE TRANSFORM FOR hstore LANGUAGE plpython3u (

    FROM SQL WITH FUNCTION hstore_to_plpython(internal),

    TO SQL WITH FUNCTION plpython_to_hstore(internal)
);
```

In practice, these commands would be wrapped up in an extension.

The contrib section contains a number of extensions that provide transforms, which can serve as real-world examples.

## COMPATIBILITY
This form of CREATE TRANSFORM is a PostgreSQL extension. There is a CREATE TRANSFORM command in the SQL standard, but it is for adapting data types to client languages. That usage is not supported by PostgreSQL.

## SEE ALSO
CREATE FUNCTION (CREATE_FUNCTION(7)), CREATE LANGUAGE (CREATE_LANGUAGE(7)), CREATE TYPE (CREATE_TYPE(7)), DROP TRANSFORM (DROP_TRANSFORM(7))